Blowing snow made traction and visibility difficult for Lions at Eagles, Vikings at Ravens, Chiefs at Redskins, and Dolphins at Steelers. Detroit running back Reggie Bush injured himself on the slippery field at the Linc in warmups and did not play in the Lions' 34-20 loss.

The snow so obscured the yard markers it was nearly impossible for fans to tell exactly where the ball was at all four stadiums. Televising networks superimposed the yard lines and numbers for viewers at home.

Time-Lapse: Linc Snow

It's was a wild Eagles games in South Philly as inches of snow -- heavy at times -- quickly moved over Lincoln Financial Field. (Published Monday, Dec. 9, 2013)

Small tractors with plows, and workers with shovels tried to clear the snow during Baltimore's 29-26 victory, to no avail. Workers used handheld snow blowers in Philadelphia, with little effect.

Conditions were at their worst in Philly, where predictions had been for a bit of snow later in the day, not a full-scale squall.

Referee Ed Hochuli told the teams during the pregame coin toss he would improvise if the coin landed on an angle. There was no need for that.

But there was need to bundle up. The Lions and Eagles huddled around portable sideline heaters. Even the cheerleaders wore winter vests.

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"It's not the same as a sunny day, that's for sure. But you've got to make adjustments," Lions quarterback Matthew Stafford said.

The Lions fumbled four times, losing one, in the first quarter alone. But after scoring in the second period, they went for a 2-point conversion — and made it — because trying a placement kick was too treacherous.

But Detroit called a timeout after going ahead 20-14 to have former Eagles kicker David Akers attempt an extra point. The Lions had been penalized 5 yards for a false start before trying a 2-point conversion, so they opted for the kick. It was blocked.

The fans that stuck this one out appeared to be having fun — and no, they weren't throwing snowballs. But with temperatures in the 20s, there were some huge gaps in the second level and upper deck.

In Baltimore, Vikings holder Jeff Locke wiped down the spot he planned to place the ball, clearing a path for kicker Blair Walsh on a field-goal try. The preparation paid off with a 39-yarder that got Minnesota within 7-3.

Swirling snow turned the field into a veritable ice rink. The players had difficulty running, passing and catching the football. The first play from scrimmage was a dropped pass by Jacoby Jones.

With fans covered with snow, the conditions seemed more appropriate for outdoors in Minnesota than Maryland. Vikings star running back Adrian Peterson, the 2012 NFL MVP, hurt his ankle on the slick turf in the second quarter.

A short drive away in the Washington suburb of Landover, the Redskins had a snow game for the first time since FedEx Field opened in 1997.

Players were slipping and sliding: Chiefs cornerback Brandon Flowers took a big-time slide trying to keep up when Pierre Garcon made a cut on a passing route. But Robert Griffin III missed making the throw. When Kansas City had the ball deep in Redskins territory, Andy Reid asked for a measurement even though the Chiefs were a full yard short of a first down. Reid couldn't judge the distance because the yard lines weren't visible.

The Chiefs went for it anyway and converted on their way to a 45-10 win.

"First time playing a game in the snow," said Kansas City's Dexter McCluster, who returned a punt 74 yards for a TD. " I love it now."

Several Dolphins came out in shorts and T-shirts during individual warmups. but the team left the field early, with the Steelers staying on the field until the usual time to head back to the locker room.

For the coin flip in Pittsburgh, Ben Roethlisberger was wearing gray sweatpants over his gold football pants.

Snow intensified after the opening kickoff, and during a stoppage in play due to an injury, a small army of workers came on the field with snow blowers to clear the hashmarks, every 5-yard stripe as well as the yardage numbers. But some of them got covered quickly as the snow picked up during Miami's 34-28 victory.